Rapid photographic record of curves of oscillographs, rheographs, and the like.



A. E. BLONDEL. RAPID PHOTOGBAPHIC RECORD OF CURVES 0F OSCILLOGRAPHS, R HEOGRAPHS, AND'THELIKE.

APPLICATION FILED AUGJ. m3.

PatentedMay 18, 1915.

2 SHEET S-SHEET I.

A. E. BLONDEL. RAPID PHOTOGRAPHIC RECORD OF CURVES 0F OSCILLOGRAPHS, RHEQGRAPHS, AND THE LIKE.

APPLICATION FILED AUG-5. I983.

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ANDRE E. BLONDEL, or rams, nuance.

min rno'rocnarmc RECORD or canvas or oscm'noonsrns, nnnocmarnsg rim LIKE.

Specification of Letters Patent: I Patented May 18 1915, 1

Application filed August 5, 1513. Serial No. 783,207.

T all whom it may) concern Be it known that I, ANDRE: E. Bnononp, a citizen of the Republic of France, residing at Paris, France, have invented new and useful Improvements in and Relating to Rapid Photographic Records of Curves of Oscillographs, Rheographs, arid the like; and I do hereby declare the following to be a full, clear, and exact description of the same.

In French specification No. 419118 are described various devices for direct observation of curves produced by the vibration of i ing photographed.

movable parts, while the recording of the curves themselves is effected by means of photographic apparatus placedat the back of a dark chamber.

y In French additional patents are described various improvements of the photographic a1 -m-ratus.

Theolnect of the present invention is to improve the conditions in which the curves are -gbserved, by a better arrangement of the electric lamp, which is used for lighting the mirrors of the recording apparatus, and

by a device enabling a portion of the rays reflected by the said mirrors to be utilized for observing the curves while they are be- Figures 1 and 2 which show respectively in horizontal cross-section and in vertical section, the optical arrangement in 0. diagrammatic manner, will -clearly show what constitutes-the improvements and in What they differ fromthe arrangements already known for apparatus of this kind in which a photographic apparatus recorder is arranged" opposite the apparatus the deflections of which are'to be registered.

In order to simplify the matter, the said drawing shows a recording apparatus con sisting of a simple cylinder 10 assumed to'be covered with sensitized paper, but'flit is ob} vious that the device in question can he replaced by any other photographic arran e ment bringing about quick movement 0 a.

photographic emulsion, that is to say, as

described in French specification No.419118.

In the same way, the apparatus, .the'deflections of which. are to be recorded, is represented here simply by small mirrors 2, each assumed-to be oscillating about a vertical axis. Only one of these mirrors is shown in the vertical section (Fig. 2), while three of them, m, m", m", are shown in plan. In reality, they can be of any desired number and placed quite close to each other, i so as to be easily lightedby one and the same source of light, the rays of which are isolated and directed by diaphragms having vertical slots 25.

In the apparatus described in French specification, No. 419118, the, mirrors in question were lighted generally by an arc lamp, the crater of which is shown in Figs. 1 and 2 at A. This lamp is arranged at the side or at the back of the recording drum 10 and sends its rays through one or more cylindrical condenser lenses such as 31 and 11 with the axes of their cylindrical surfaces vertical (or through any other condenser system) on to the mirrors m. These raysare oblique relatively to the horizontal axis X Y of the apparatus. The result is that the apparatus is fairly cumbersome, and that various deformations can be produced by the obliquity of the rays passing through the lenses.

The rays refracted by the mirrors 2, are concentrated on the photographic emulsion by means of another cylindrical lens 12, in front of which itis advisable to interpose a first condenser ,lens 11, as explained in French specification No. 419118. But the arrangements which will be described accoreiling to the present invention, are also ad-' vantageously applicable even when the said lens 11 is done away with. In any case, Whatever be the number of the-lenses, care must be taken that the conjugate foci of the mirrors 2 should coincide with the photographic emulsion.

. As already stated, the arrangement of the luminous source at A has disadvantages owing to the obli uity of the rays. The same is the, case i placed at A" and the rays are directed onto the mirror 2 by means ofan intermediate mirror-31, for in that case there would still be obliquity and unsymmetrical arrangement of the apparatus. Another solution which has also been tried, consists in placing the source of light at A in the horizontal plane passing through X Y and in sending the -rays back to the mirror 2 by means of a the source of light is 1), back to the mirror 2. The

' which ing to this invention, consists in the electric are or source of light being placed on the left of the drum 10 in the figures, in the vertical plane passing through X Y, at a higher (or even lower) level than that of the' mirror 2, and in the apparatus thus being rendered symmetrical, While still allowing the photographic recording to be effected at 10. Fig. 2 shows an example of this arrangement.

3 is the are formed between the carbons a, b, arranged in any desired manner, but so that .the crater of the ositive carbon (4 should project its rays'e ectively on a mirror 4 at a right angle to the plane of Fig. 2, whichisends the pencil of rays, by means of a cylindrical lens 8 (or a spherical one, ac cording to circumstances, not shown in Fig. pencil of rays passes through a plate or diaphragm 25 normal to its axis and provided with one or more slots, in order to limit narrowly the pencils falling on the mirrors 2. Owing to the concentration by the cylindrical lenses 11, 12,- each of the said pencils gives on the drum 10 an image forn'iing practically a luminous point, the dimensions of which de pend on the dimensions of the mirrors m, m, m. The characteristic feature of this arrangement is. that the apparatus becomes perfectly symmetricahthe arc does not interfere withthe operator who stands near the drum, and the luminous pencils pass through the lenses with the least possible obliquity.

In ordinary cases, the luminous rays sent back by the mirrors 2, will .meet as already explained with referenceto Fig. 4' of the French specification No. 419118, a lens-L and amirror M oscillating about an axis 0,

so as to produce an image on opaque glass 1% (the iinage could also be observed by looking direct at the oscillating mirror, or the said mirror could be replaced by a rotating .spiraloid drum of the'Siemcns type). At the moment of taking the photograph, the lens L and the mirror M are lowered by means of a lever K movable about an axis T.

Ihis operation proves disadvantageous.

second improvement according to this invention consists therefore in. avoiding the use of this oscillating mirror and of'the manipulation which it requires. To that end, incident rays falling on the mirrors, 2, is sent back separately on to a cylindrical lens 3 and falls on a mirror 9 can be either oscillating like the mirror M (see Fig. 4 of the French specification No. 4191.19) or rotating about an axis Z.

Tnthat case. a polygonal mirror-is prefer ably used. Thus Fig. 2 shows a mirror with four silvcrcd faces, for the purpose of ob taining greater continuity'in lighting.

through the lens 1] 'prcssed against the end carbons a]; or 07/. r

which is l 3 given a greater height. It forms thus a. r-

tion of the large principal pencil sent ck by the'lens 11, and it is a portion of the said large pencil which is sent back to'the rotating or oscillatin mirron In both cases, as will be seen igs. 2 and 8), it is possible to observe the rays sent back by the mirror 9, While the photograph is being taken by means of the rays condensed by the lens 12. I 1 i Fig. 4 shows a practical method of carrying out the invention. 'A case 1 (for instance of metal, closed at each side by shutters of wood or metal) contains the galvanometric system 2. The latter receives the light of a suitable are lamp 3, so as to send the rays on to the mirror 4. The inclination of the latter is adjusted by means of a screw a toothed quadrant The mirrorbeing of the screw by means of a spring, the rays are sent back by the mirror 4: to the galvanometers 2, passing through the lens 8'. A portion of. the pencil of rays is sent back to the recorder lO by the cylindrical lenses ll and 12' (or by the lens 12 alone, if a single lens system is used). Another. portion is sent back by the cylindrical lens 13/to the rotating or oscillating mirror 9.

Fig. 5 shows several i' her modifications of the process for, lighting. the mirrors 2. F i rst of all, a modification shows the mirror 4 and the lens 8 arranged below theTeflecte'd pencil, and not above the same, the arc producing the lighting being placed at 3, below the case. butstill in the vertical plane of the axis of the apparatus. Another modification isshown on the left of the figure. An arc is produced at 21 andlights a cylindrical (or spherirml,according to circumstances) lens 22, which SGfldS-ittfiliillfiil of rays through a systen'i. of slots 25 715.9 on to a mirror 23 which. is silver-ed on the right hand side and which can be formed. according to circumstances, by a glass plate with aflat face, or on the contrary on its right face; the curves of the lens ahd the mirror 23 produce vertical concentration of rays of the are on the mirrors. Finally, a third Imodification consists in the use of a cylindrical lens 23, none'o'f the faces of which is silver-ed, and which concentrates on the mirrors? oftherays coming from the craters ofnn are 24 formed between two hese rays pass through the system of slots 25 ten 6 for instance acting on 7 or on a suitable lever.

by a cylindrical lenssilvered In the preceding figureShQG, 27 and 28,

represent opaque partitions, for the purpose are or the observation screen 142 The car- I ,.ig.'3 shows a modification of Fig. in which the pencil sent back to the lens 13, passes first bons of the arc lamp could be arranged in various manners, as shown, by way of nonhrnitative examples, in Figs. 14, and the tion.

mechanism of the arc, lamp may also be any desired. In Fig. 4, it has been assumed that one or the otherof the carbons is re- -tained by a. stop finger c, of refractory material, which makes it possible to do away with'the'who1e mechanism of thelamps, as the advance takes place graduall in ac-' 'c'o'rdance with the consumption. 11 order tofacilitate this method, are preferably used two parallel carbons a, b, suitably secured at the top in a double carbon holder which is suitably guided by uide rods, which reduces the arc lamp to its simplest construc- Having. fully described my invention, what I claim and desire to secure by Letters Patentis '1. In fpliiit'ographic recorder for oscillographs, rheographs and like instruments, the combination, with the mirror of the instrument, of a source of light; a movable means for carrying a light-sensitive surface; a lens between said source and said mirror for concentrating .rays on the latter; a pair of lenses adapted to concentrate, upon the light sensitive surface,'a portion of the bundle of rays reflected from the mirror; a screen; a

[moving reflector; and a lens adapted to transmit to said last named reflector a portion of said bundle of light to said moving reflector, whence it is condensed on said screen. I 2. In a photographic recorder for oscillographs, rheographs and like instruments, the combination, with the mirror of thc instrument, of a source of light; a movable means for carrying a light sensitive surface; a lens and slit .between said source and said mirror for limiting and concentrating rays on the latter; a pair of lenses'adapted to concentrate, upon the light sensitive surface, a portion of the bundle of rays reflected from the mirror; a screen; a moving reflector; and a cylindrical lens adapted to transmit to saidcombination, with the mirror of the instrulast named reflector a portion of said bundle of light to said moving reflector, whence it is condensed on said screen, the bundles of rays incident on. and reflected from said-mirror lying in nearly the same plane and forming between each other the most acute practicable angle.

3. In a photographic recorder for oscillographs, rheographs and like instruments, the

ment, of a source of light; a movable means for carrying a light sensitivesurface; a lens "and slit between said source and said mirror for concentrating rays of the latter; a pair of .cylindrical lenses adapted to concentrate,

incident on and reflected from said mirror lyingapproximately in the same plane.

4. In a photographic recorder for oscillographs, rheographs and like instruments, the

combination, with the mirror of the instru ment, of a source of light; a movable means said light sensitive surface; a condensing means adapted to transmit another portion of said again reflected rays; a screen; and a movable reflector for reflecting the rays from said last named condensing means onto said screen. I

5. In a photographic recorder for oscillographs, rh eographs and like instruments,the combination, with the mirror of the instrument, of a source of light; a movable means for carrying a light sensitive surface; a reflector adapted to reflect light rays from said source; a condensing means for concentrating the rays from said reflector ontothe mirror, whence the rays are again reflected means for condensing one portion of the bundle of again reflected rays upon said li ht sensitive surface; a condensing means a apted to transmit another portion of said ment, of a source of light; amovable means.

for carrying a light sensitive surface; a reflector adapted to reflect light rays from said source a condensing means for concentrating the rays from said reflector onto the mirror, whence the rays are again reflected; means for condensing one portion of the bundle of again reflected rays upon said light sensitive surface; a condensing means adapted to transmit another portion of said again reflected rays; a screen; and a movable reflector for reflecting the rays from said last named condensing means onto said screen, an active point of each condensing means, reflector, mirror and light sensitive surface lying approximately in\a common pl n a 7. In a photographic recorder for oscillographs, rheographs and like instruments,the combination, with the mirrors of a'plurality of instruments, of a source of light;'a movable means for carrying a light sensitive surface; a reflector adapted to reflect light rays from said source; a condensing means for too concentrating separate bundles'of rays from flector, mirror and light sensitive surface said reflector onto each of the mirrors, lying nearlyine common vertical plane for whence the rays are again reflected; means each of the separate bundles of rays. w for condensin one portion of the bundles'of In testimony whereof, I have signed my\;15

5 again reflecte rays upon said light sensitive name to this specification in the presence of surface,- a condensing means adapted to jtwosubscribing witnesses. transmit another portion of said again re- 'fiected z ays; a screen; and a movable. re- ANDRE BLONDEL" L flector for reflecting the rays from said lust Wit: i I 10 named condensing means onto said screen, ANeizLE'BoUcnnnoN, 'I If an active point of each condensing means, re- FRANK H; MASON. 

